I know a lot of people who worked for members of Congress and a few who do now. Computers sitting on desks in regular Congressional offices do not have access t

I know a lot of people who worked for members of Congress and a few who do now. Computers sitting on desks in regular Congressional offices do not have access to classified materials. Most members of Congress or their staff do not have access to classified material at all. There is a lot of private information on those computers, though, and the biggest risks there are the use of that info to harass staff and/or manipulation of it to feed conspiracy theories (see: Pizzagate). Blackmail material is extremely unlikely since these are all government computers and everyone who works there knows they are subject to oversight.